1. Field of the Invention
The present invention relates generally to computer integrated manufacturing and, more particularly, to a system and method for integrating a computerized business system with a computerized manufacturing system.
2. Related Art
Recent developments in computer and computer-related technology have enabled the use of computers in numerous business applications. Almost every facet of today's industry is implemented using computer systems in some manner. Computerization has become necessary for businesses to remain in a competitive posture.
Computer systems are used to automate processes, manage large quantities of information, and provide fast, flexible communications. One area enjoying widespread computerization is that of the business environment. Many businesses from small stores, to professional offices and partnerships, to large corporations have computerized their business functions to some extent. Computerized business functions can include billing, order-taking, scheduling, inventory control, record keeping, and the like. Such computerization can be accomplished by using a business applications system, running business applications software packages.
There are many business applications software packages available to handle a wide range of business functions, including those discussed above. One such package is the SAP R/2 System available from SAP America, Inc., 625 North Governor Printz Blvd., Essington, Pa. 19029.
The SAP R/2 System is a business applications software package designed to run on an IBM or compatible mainframe in a CICS (Customer Interface Control System) or IMS (Information Management System) environment. For example, SAP may use CICS to interface with terminals, printers, databases, or external communications facilities such as IBM's Virtual Telecommunications Access Method (VTAM).
SAP is a modularized, table driven business applications software package that executes transactions to perform specified business functions. These functions may include order processing, inventory control, and invoice validation; financial accounting, planning, and related managerial control; production planning and control; and project accounting, planning, and control. The modules that perform these functions are all fully integrated with one another.
Another area that has been computerized is the manufacturing environment. Numerous manufacturing functions are now controlled by computer systems. Such functions can include real-time process control of discrete component manufacturing (such as in the automobile industry) and process manufacturing (such as chemical manufacturing through the use of real-time process control systems).
Directives communicated from the business systems to the manufacturing systems are commonly known as work orders. Work orders can include production orders, shipping orders, receiving orders, and the like.
However, the computerization of business systems within the business environment and the computerization of manufacturing systems within the manufacturing environment have followed separate evolutionary paths. This often results in an incompatibility between the different systems. Specifically, work orders communicated from the business systems may have a context and a format which are not readily compatible with the context and format recognized by the manufacturing systems. Additionally, the business systems may not provide all the information necessary for the manufacturing systems to carry out designated functions.
The inventors are not aware of a generic computerized solution that offers an efficient, automated way to integrate the computerized business systems with the full spectrum of computerized manufacturing systems.
According to conventional wisdom, integrating the computerized business systems with the computerized manufacturing systems often requires a human interface. Consequently, a high degree of automation of plant operations is not accomplished, and neither is full automation of inventory operations. In this solution, work orders are generated by the business systems indicating parameters such as: the product to be manufactured, the required date, the raw materials needed, and the like. Human operators receive the work order along with these parameters and manually prepare work order instructions that enable the computerized manufacturing systems to manufacture the product specified by the work order. Human operators are also responsible for collecting data from the manufacturing systems and providing this data to the computerized business systems.
Another conventional solution is to implement a custom, computerized interface between the business systems and the manufacturing systems. However, these custom solutions are usually tailored to a specific situation. As a result, the tailored solution is not portable into other situations without major modifications. Additionally, these solutions are costly to maintain over time because of inherent difficulties in accommodating change.
In many manufacturing plants, multiple real-time process control systems are implemented to control manufacturing. One problem with having multiple real-time process control systems is that all interfaces to those computers are not necessarily uniform. In such a situation, a process information system (also referred to as a process control supervisory computer) may be provided to serve as a consistent interface to multiple, real-time process control systems having different interface characteristics. The process information system allows operators to provide data to specific real-time process control systems and retrieve data about the manufacturing process from those real-time process control systems.
In typical manufacturing plants, there are diverse manufacturing situations calling for different solutions. These situations include characterizing manufacturing output as relating to either a period of time during which manufacturing occurs or a quantity of material manufactured. In other words, output can be characterized with either time-based units or physical quantity units.
For the purpose of this document, these characterizations are described in terms of two types of manufacturing paradigms: batch manufacturing and continuous manufacturing. The batch manufacturing paradigm depicts manufacturing as producing a finite quantity of products in physical-quantity units such as lots or batches. The lots or batches manufactured may not be consistent from one manufacturing run to the next. The continuous manufacturing paradigm, on the other hand, depicts manufacturing as producing a theoretically consistent product over time in an ongoing manner. Both paradigms can be used to characterize the manufacturing output of a given plant in order to fulfill different business needs. A continuous plant can be defined as a theoretical implementation of the continuous paradigm. A batch plant can be defined as a theoretical implementation of the batch paradigm.
Continuous plants generally manufacture a fixed set of products, while batch plants are generally capable of being reconfigured to manufacture many different products using many different recipes. For continuous plants, the production unit can be described in terms of a set time frame. However, for batch plants, the unit of manufacture is not a set time frame. Instead, the unit of manufacture is a lot which can be defined by certain characteristics. These characteristics can include, for example, an event indicating the time of the start of the lot, an event indicating the time of the completion of the lot, a value indicating the magnitude of the lot, and other quality related attributes which are characteristic of all subparts or subdivisions of the lot.
Many batch plants use the same equipment to make several different products according to different recipes. Because different recipes are used and different product requirements exist for each batch, information handling requirements for each batch are different. In these plants, it is desirable to report different sets of manufacturing information for different recipes manufactured. In contrast, reporting requirements for continuous plants are usually ideally met by providing the same set of manufacturing data at regular, periodic intervals.
Apparently, conventional interfaces to meet all of the needs for collecting, retrieving, and reporting data for a multitude of batch and continuous plants incorporating different real-time process control systems do not exist.
An example of a conventional solution is the DASS system, available from SAP AG, of Waldorf, Germany. The DASS system appears to be targeted at creating a manufacturing schedule rather than automatically creating a production order instruction and transmitting it to a real-time process control system. DASS receives information used in setting manufacturing schedules from the SAP R/2 package, and collects data from the real-time process control system to provide status information on those items scheduled. DASS does not appear to provide a mechanism for executing work orders whereby setpoints are computed and transmitted to the real-time process control systems in the computerized manufacturing system. Further, DASS does not appear to provide a generic solution to connect a computerized business system to a computerized manufacturing system which will collect data relating to the execution of work orders, and, therefore, does not appear to provide a comprehensive manufacturing execution system interface solution.
What is needed is a computerized interface between computerized business systems in the business environment and computerized manufacturing systems in the manufacturing environment that enables a true computer integrated manufacturing environment. The ideal computerized interface should be capable of handling the information needs of a full spectrum of manufacturing processes, and should be able to interface to a number of different real-time process control systems.